SI-8001FFE DC-to-DC Step-Down Converter Features and Benefits Description 3.5 A output current supplied in a small, through-hole mount power package High efficiency: 83% at VIN = 15 V, IO = 2.0 A,VO = 5 V Requires only six external components (optional soft start requires an additional capacitor) Oscillation circuit built-in (frequency 300 kHz typical) Constant-current mode overcurrent protection circuit and overtemperature protection circuit built-in Soft start function built-in (can be implemented as an on/off function; output-off state at low level) Low current consumption during output-off state The SI-8001FFE DC voltage regulator is a DC-to-DC buck convertor that attains an oscillation frequency of 300 kHz, and has an integrated miniaturized choke coil, allowing it to serve as a small, high efficiency power supply in a compact TO220F package. The internal switching regulator function provides high efficiency switching regulation without any need for adjustment. The device requires only six external support components. The optional soft start function requires an additional capacitor. Optional on/off control can be performed using a transistor. The SI-8001FFE includes overcurrent and overtemperature protection circuits. Applications include: DVD recorder FPD TV Telecommunications equipment Office automation equipment, such as printers On-board local power supply Output voltage regulator for second stage of SMPS (switched mode power supply) Package: TO220F-5 Not to scale Functional Block Diagram VIN 1 IN SW C1 PReg On/Off Soft Start Latch and Driver C2 R1 Osc Comparator C3 Overtemperature Protection Error Amplifier GND 3 ADJ 4 R2 Reference Voltage 27469.057 VOUT L1 Di RK-46 (Sanken) Overcurrent Protection Reset 5 SS 2 SI-8001FFE DC-to-DC Step-Down Converter Selection Guide Part Number Output Voltage Adjustable Range (V) Efficiency, Typ. (%) Input Voltage, Max. (V) Output Current, Max. (A) SI-8001FFE 0.8 to 24 83 40 3.5 Packing 50 pieces per tube Absolute Maximum Ratings Characteristic DC Input Voltage Power Dissipation Junction Temperature Symbol Remarks VIN Rating Units 43 V PD1-1 Connected to infinite heatsink; TJ(max) = 150C, limited by internal overtemperature protection. 22.7 W PD1-2 Connected to infinite heatsink; TJ = 125C. 18.2 W PD2-1 No heatsink; TJ(max) = 150C, limited by internal overtemperature protection. 2.15 W PD2-2 No heatsink; TJ = 125C. 1.72 W -40 to 150 C Internal overtemperature protection circuit may enable when TJ 130C. During product operation, recommended TJ 125C. TJ Storage Temperature Tstg -40 to 150 C Thermal Resistance (junction-to-case) RJC 5.5 C/W Thermal Resistance (junction-to-ambient air) RJA 58 C/W Min. Max. Units See remarks 40 V 0.8 24 V 0 3.5 A -30 125 C -30 85 C Recommended Operating Conditions* Characteristic Symbol DC Input Voltage Range VIN DC Output Voltage Range VO DC Output Current Range Remarks VIN (min) is the greater of 4.5 V or VO+3 V. VIN VO + 3 V; to be used within the allowable package power dissipation characteristics (refer to Power Dissipation chart). IO Operating Junction Temperature Range TJOP Operating Temperature Range TOP To be used within the allowable package power dissipation characteristics (refer to Power Dissipation chart). *Required for normal device functioning according to Electrical Characteristics table. All performance characteristics given are typical values for circuit or system baseline design only and are at the nominal operating voltage and an ambient temperature, TA, of 25C, unless otherwise stated. Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 2 SI-8001FFE DC-to-DC Step-Down Converter ELECTRICAL CHARACTERISTICS1, valid at TA = 25C, VO = 5 V (adjusted), R1 = 4.2 k, R1 = 0.8 k Characteristic Symbol Reference Voltage VADJ Reference Voltage Temperature Coefficient VADJ /T Typ. Max. Units 0.800 0.816 V VIN = 15 V, IO = 0.2 A, TC = 0 to 100 C - 0.1 - mV/C VIN = 15 V, IO = 2 A - 83 - % fO VIN = 15 V, IO = 2 A 270 300 330 kHz - - 80 mV Line Regulation VLine VIN = 10 to 30 V, IO = 2 A Load Regulation VLoad VIN = 15 V, IO = 0.2 to 3.5 A Overcurrent Protection Threshold Current Min. 0.784 Efficiency2 Operating Frequency Test Conditions VIN = 15 V, IO = 0.2 A IS VIN = 15 V SS Terminal On/Off Operation Threshold Voltage VSSL SS Terminal On/Off Operation Outflow Current ISSL Quiescent Current 1 Iq Quiescent Current 2 Iq(off) - - 50 mV 3.6 - - A - - 0.5 V VSSL = 0 V - 6 30 A VIN = 15 V, IO = 0 A - 6 - mA VIN = 15 V, VSS = 0 V - 200 600 A 1Using circuit shown in Typical Application Circuit diagram. 2Efficiency is calculated as: (%) = ([V x I ] x [V x I ]) x 100. O O IN IN Pin-out Diagram Terminal List Table Name Number Function IN 1 Supply voltage SW 2 Regulated supply output GND 3 Ground terminal ADJ 4 Terminal for resistor bridge feedback The SS terminal is used to enable soft start and to control on/off operation of the IC output, VO (see figure 2). If neither soft start nor on/off control is used, leave pin open. SS 5 To enable soft start, connect a capacitor between SS and ground. To control on/off operation, connect an NPN bipolar transistor, in a TTL open collector output configuration, between the SS terminal and GND. Turn off is done by decreasing VSSL below its rated level. When both soft start and VO on/off are used, a protection measure such as current limiting is required because, if the capacitance of C3 large, the discharge current of C3 flows across the transistor for on/off operation. Because a pull-up type resistor is provided inside the IC, no external voltage can be applied. 1 2 3 4 5 SI-8000FFE SS 5 System TTL SI-8000FFE SI-8000FFE SS 5 SS 5 C3 System TTL (a) VO on/off control only (b) Soft start only C3 (c) VO on/off and soft start control Figure 2. Alternative configurations for SS pin. If neither soft start nor VO on/off is required, the SS pin is left open. Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 3 SI-8001FFE DC-to-DC Step-Down Converter Performance Characteristics At TA = 25C, VO = 5 V Adjusted, R1 = 4.2 k, R2 = 0.8 k 6.00 90 15 V Efficiency versus Output Current VO= 3.3 V (%) 80 0.5 A VIN 4.00 Low Voltage Behavior: Output Voltage versus Supply Voltage 20 V 75 30 V 70 40 V VO (V) 8V 0 0.5 1.0 1.5 2.0 IO (A) 2.5 3.0 0 3.5 1 2 3 4 5 VIN (V) 5.08 15 V 85 VIN 6 7 8 VIN 5.06 5.04 20 V 75 Load Regulation: 5.02 Output Voltage 5.00 versus Output Current 4.98 40 V 4.96 10 V VO (V) 80 (%) 0 5.10 8V 30 V 70 40 V 30 V 15 V 4.94 65 60 3.5 A 1.00 90 Efficiency versus Output Current VO= 5.0 V 1A 2A 3.00 2.00 65 60 0A IO 5.00 85 8V 4.92 4.90 0 0.5 1.0 1.5 2.0 IO (A) 2.5 3.0 0 3.5 100 1 2 IO (A) 10 20 VIN (V) 3 10 95 VIN 20 V 15V 8 Quiescent Current versus Supply Voltage IO = 0 A SS pin open 85 30 V 80 Iq (mA) Efficiency versus Output Current VO= 12.0 V (%) 90 40 V 6 4 2 75 0 70 0 0.5 1.0 1.5 2.0 IO (A) 2.5 3.0 3.5 400 0 30 40 6 5 8V 300 Overcurrent Protection: Output Voltage versus Output Current 200 4 VO (V) IQ (A) Behavior at Turn-Off: Quiescent Current versus Input Voltage IO = 0 A VSS = 0 V VIN 15 V 3 30 V 2 40 V 100 1 0 0 0 0.5 1.0 1.5 2.0 VIN (V) 2.5 3.0 3.5 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 0 1 2 IO (A) 3 4 5 4 SI-8001FFE DC-to-DC Step-Down Converter Thermal Performance Characteristics The application must be designed to ensure that the TJ(max) of the device is not exceeded during operation. To do so, it is necessary to determine values for maximum power dissipation, PD(max), and ambient temperature, TA(max). Power Dissipation versus Ambient Temperature Shin Etsu G746 silicon grease 24 Infinite heat sink TJ(max) = 150C 22 PD can be calculated from input values: 100 V - 1 - VF I O 1 - O PD = VO I O Hx VIN 20 Infinite heat sink TJ(max) = 125C 18 where: 16 VO is output voltage in V, Al heat sink 200 mm x 200 mm x 2 mm RJA = 2.3C/W TJ(max) = 125C PD (W) 14 VIN is input supply voltage in V, IO is output current in A, Al heat sink 100 mm x 200 mm x 2 mm RJA = 5.2C/W TJ(max) = 125C 12 10 x is IC efficiency in percent (varies with VIN and IO; refer to efficiency performance curves for value), and VF is forward voltage for the input diode, Di. In these tests, the Sanken RK46 was used, at 0.5 V and IO = 3.5 A. For application design, obtain thermal data from the datasheet for the diode. PD is substantially affected by the heat conductance properties of the application, in particular any heatsink connected to the device radiation fin. The relationships of PD, TA, and heatsink type is represented in the Power Dissipation chart. 8 Al heat sink 75 mm x 75 mm x 2 mm RJA = 7.6C/W TJ(max) = 125C 6 4 No heat sink TJ(max) = 150C 2 0 -40 No heat sink TJ(max) = 125C -20 0 20 40 60 80 TA (C) Because the heat dissipation capacity of the heatsink depends substantively on how it is used in the actual application, thermal characteristics of the application must be confirmed by testing. The internal overtemperature protection circuit may enable when TJ 130C. 6 OTP On 5 VIN = 15 V, IO = 10 mA 4 VO (V) Overtemperature Protection: Output Voltage versus Junction Temperature 3 2 1 OTP Off 0 0 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 20 40 60 80 100 TJ (C) 120 140 160 180 5 SI-8001FFE DC-to-DC Step-Down Converter Component Selection tures. Do not use either OS or tantalum types of capacitors for C2, because those cause an abnormal oscillation. Diode Di A Schottky-barrier diode must be used for Di. If other diode types are used, such as fast recovery diodes, the IC may be destroyed because of the reverse voltage applied by the recovery voltage or ON voltage. C3 is required only if the soft start function is used. If not using soft-start, leave the SS terminal open. A pull-up resistor is provided inside the IC. Choke Coil L1 If the winding resistance of the choke coil is too high, the efficiency may be reduced below rating. Because the overcurrent protection start current is approximately 4.2 A, attention must be paid to the heating of the choke coil by magnetic saturation due to overload or short-circuited load. Resistor Bridge R1 and R2 comprise the resistor bridge for the output voltage, VO, and are calculated as follows: (V - V ) (V - 0.8) () , and R2 = VADJ = 0.8 = 0.8 (k ) R1 = O ADJ = O -3 -3 1 x 10 IADJ Capacitors C1, C2, and C3 Because for SMPS, large ripple currents flow across C1 and C2, capacitors with high frequency and low impedance must be used. If the impedance of C2 is too high, the switching waveform may not be normal at low tempera- IADJ 1 x 10 IADJ should always be set to 1 mA. Note that R2 should always be present to ensure stable operation, even if VO, is set to 0.8 V (that is, even if there is no R1). VO should be at least VIN + 8%. Typical Application Diagram VIN L1 1 Component SW SI-8001FFE ADJ SS GND 3 5 C1 GND VO 2 IN C1 C2 C3 Di L1 R1 4 IADJ Di R2 Rating 470 F 680 F 0.1 F (For soft start function) RK-46 (Sanken) 47 H C2 C3 Soft Start Only GND Recommended PCB Layout GND GND U1 C2 C1 Vin C3 C1 C2 U1 R2 C3 R1 S1 S1 Vadj/Vos D1 R1 D1 Vout Vadj/Vos R2 Vin Vsw Vout L1 L1 Vsw All external components should be mounted as close as possible to the SI-8001FFE. The ground of all components should be connected at one point. Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 6 SI-8001FFE DC-to-DC Step-Down Converter PACKAGE OUTLINE DRAWING 4.70.2 2.54 0.2 10.16 0.2 0.7 3. XXXXXXXX XXXXXXXX Branding XXXXXXXX 2 0. 2 2.76 0.2 XXXXXXXX ( 17. 9) 15. 87 0. 2 5. 4 6. 68 0. 2 3. 3 0. 1 7 ( 2) (4-R1) 0.8 R-end +0.1 -0.05 4. 3 0. 6 0.6 +0.2 4 x 1.70.6 = (6.8) 0.5 -0.1 4.3 0.7 8.2 0.7 Leadframe: 1113A Branding codes (exact appearance at manufacturer discretion): Leadform: 1113A Weight: 2.3 g typical Dimensions in millimeters 1st line, type: 8001FFE 2nd line, lot: SK YMW Where: Y is the last digit of the year of manufacture M is the month (1 to 9, O, N, D) W is the week of the month (1 to 5) 3rd line, tracking number: nnnn RoHS directive compliant Device pins lead (Pb) free Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 7 SI-8001FFE DC-to-DC Step-Down Converter PACKING SPECIFICATION 14.0 0.7 528 7 1.2 A 1.5 ANTISTATIC 12.6 12.0 10.6 34.0 8 5.2 1.8 A View A-A Tube 50 pieces per tube 3.9 5.5 5.0 14.4 View A-A Enlargement 570 50 H 155 Inner Carton 12 tubes per carton 600 pieces per inner carton L W Dimensions in mm Carton Type L W H Quantity Outer Carton A 580 180 140 2 inner cartons, 1200 pieces per outer carton Outer Carton B 580 335 140 4 inner cartons, 2400 pieces per outer carton Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com Outer Carton (See table) 8 SI-8001FFE DC-to-DC Step-Down Converter WARNING -- These devices are designed to be operated at lethal voltages and energy levels. Circuit designs that embody these components must conform with applicable safety requirements. Precautions must be taken to prevent accidental contact with power-line potentials. Do not connect grounded test equipment. The use of an isolation transformer is recommended during circuit development and breadboarding. Cautions for Use * Operation of the product in parallel to increase current is not permitted. * Although the product has an internal overtemperature protection circuit, that is intended only to protect the product from temporary excess heating due to overloads. Long-term reliability cannot be guaranteed when the product is operated under continuous overload conditions. Because reliability can be affected adversely by improper storage environments and handling methods, please observe the following cautions. Cautions for Storage * Ensure that storage conditions comply with the standard temperature (5C to 35C) and the standard relative humidity (around 40 to 75%); avoid storage locations that experience extreme changes in temperature or humidity. * Avoid locations where dust or harmful gases are present and avoid direct sunlight. * Reinspect for rust on leads and solderability of products that have been stored for a long time. Cautions for Testing and Handling When tests are carried out during inspection testing and other standard test periods, protect the products from power surges from the testing device, shorts between adjacent products, and shorts to the heatsink. Remarks About Using Silicone Grease with a Heatsink * When silicone grease is used in mounting this product on a heatsink, it shall be applied evenly and thinly. If more silicone grease than required is applied, it may produce stress. * Volatile-type silicone greases may permeate the product and produce cracks after long periods of time, resulting in reduced heat radiation effect, and possibly shortening the lifetime of the product. * Our recommended silicone greases for heat radiation purposes, which will not cause any adverse effect on the product life, are indicated below: Type Suppliers G746 Shin-Etsu Chemical Co., Ltd. YG6260 GE Toshiba Silicone Co., Ltd. SC102 Dow Corning Toray Silicone Co., Ltd. Heatsink Mounting Method Torque When Tightening Mounting Screws. The recommended tightening torque for this product package type is: 58.8 to 68.6 N*cm (6.0 to 7.0 kgf*cm). Soldering * When soldering the products, please be sure to minimize the working time, within the following limits: 2605C 10 s 3505C 3 s * Soldering iron should be at a distance of at least 1.5 mm from the body of the products Electrostatic Discharge * When handling the products, operator must be grounded. Grounded wrist straps worn should have at least 1 M of resistance to ground to prevent shock hazard. * Workbenches where the products are handled should be grounded and be provided with conductive table and floor mats. * When using measuring equipment such as a curve tracer, the equipment should be grounded. * When soldering the products, the head of soldering irons or the solder bath must be grounded in other to prevent leak voltages generated by them from being applied to the products. * The products should always be stored and transported in our shipping containers or conductive containers, or be wrapped in aluminum foil. Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 9 SI-8001FFE DC-to-DC Step-Down Converter The products described herein are manufactured in Japan by Sanken Electric Co., Ltd. for sale by Allegro MicroSystems, Inc. Sanken and Allegro reserve the right to make, from time to time, such departures from the detail specifications as may be required to permit improvements in the performance, reliability, or manufacturability of its products. Therefore, the user is cautioned to verify that the information in this publication is current before placing any order. The information included herein is believed to be accurate and reliable. Application and operation examples described in this document are given for reference only and Sanken assumes no responsibility for any infringement of industrial property right, intellectual property rights or any other rights of Sanken or any third party which may result from its use. When using the products herein, the applicability and suitability of such products for the intended purpose shall be the users responsibility to determine. Although Sanken undertakes to enhance the quality and reliability of its products, the occurrence of failure and defect of semiconductor products at a certain rate is inevitable. Users of Sanken products are requested to take, at their own risk, preventative measures including safety design of the equipment or systems against any possible injury, death, fires or damages to society due to device failure or malfunction. Sanken products listed in this document are designed and intended for the use as components in general purpose electronic equipment or apparatus (home appliances, office equipment, telecommunication equipment, measuring equipment, etc.). When considering the use of Sanken products in the applications where higher reliability is required (transportation equipment and its control systems, traffic signal control systems or equipment, fire/crime alarm systems, various safety devices, etc.), please contact your nearest Sanken sales representative to discuss and obtain written confirmation of your specifications. The use of Sanken products without the written consent of Sanken in the applications where extremely high reliability is required (aerospace equipment, nuclear power control systems, life support systems, etc.) is strictly prohibited. Anti-radioactive ray design is not considered for the products listed herein. Copyright (c) 2007 Allegro MicroSystems, Inc. This datasheet is based on Sanken datasheet SSJ-03144 For the latest version of this document, visit our website: www.allegromicro.com Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 10